Expansion joint filler

ABSTRACT

An expansion joint assembly used between concrete slabs. A lower expansion joint strip that becomes permanently positioned between the concrete slabs and a removable topping strip that exposes a controlled depth groove above the expansion joint strip for receiving a sealant. In a modification, the upper edge of the expansion joint strip is coated with a material that will not bond or adhere to the sealant, permitting unrestricted lateral expansion and contraction of the sealant.

United States Patent [72] Inventor Clarence A. Klittich St. Louis, Mo.21 Appl. No. 887,173 [22] Filed Dec. 22, I969 [45] Patented Dec. 28,1971 [73] Assignee MFG Associates, Inc.

St. Louis, Mo.

[54] EXPANSION JOINT FILLER 6 Claims, 6 Drawing Figs.

[52] U.S. Cl 52/396, 94/ 18.2 [51] Int. Cl EOIc 11/10 [50] Field ofSearch ..94/l6, 18.2; 52/726, 730, 410. 376, 396

[5 6] References Cited UNITED STATES PATENTS 1,675,226 6/1928 Munroe52/376 1,934,651 11/1933 Anderson.. 52/410 2,039,398 5/1936 Dye 52/720 XPrimary Examiner-John E1 Murtagh Altorney- Kingsland, Rogers, Ezell,Eilers & Robbins ABSTRACT: An expansion joint assembly used betweenconcrete slabs. A lower expansion joint strip that becomes permanentlypositioned between the concrete slabs and a removable topping strip thatexposes a controlled depth groove above the expansion joint strip forreceiving a sealant. In a modification, the upper edge of theexpansionjoint strip is coated with a material that will not bond oradhere to the sealant, permitting unrestricted lateral expansion andcontraction ofthe sealant.

EXPANSION JOINT FILLER BRIEF DESCRIPTION OF THE INVENTION This expansionjoint assembly comprises a lower expansion joint strip and an uppertopping strip fastened together by staples or other mechanical means.The upper strip is removable after the expansion joint assembly has beenpositioned between concrete slabs and after the concrete has set. Theexposed groove is then filled with sealant to provide a liquidtight sealbetween the concrete slabs.

The expansion joint strip and topping strip are made of compressed woodfiber sawed to form the two pieces. The result, after removal of thetopping strip, is a clean groove with square caulking corners. Thesealant will readily adhere to the concrete slabs because the wood fiberexpansion joint strip material leaves no contaminating film. It isnotable that the assembly meets the requirements of ASTM D-l 751 TypeIII and Federal Specification HI-I-F-34le. No film is left on thesurface of the concrete as would be the case if other materials, such aspolystyrene or asphalt-impregnated fiber board, were used. Furthermore,routing of the expansion joint strip to make a groove for receivingsealant is eliminated and instead, the topping strip can be quickly andeasily removed leaving a groove of unifonn depth controlled by theheight of the topping strip.

In a modification of the invention, the upper edge of the expansionjoint strip is coated with a material that will not bond to the sealant.This coating may be in the form of a tape, such as an ethylene tape,glued to the upper edge of the expansion joint strip, or may be a liquidmaterial applied to the upper edge of the expansion joint strip that,when dry, will not bond to the sealant. The advantage of thismodification is that the sealant will bond only to the adjacent sideedges of the concrete slabs, and the absence of a bond to the coatingmaterial leaves the sealant free to expand and contract laterally withexpansion and contraction of the concrete in varying weather conditions.

In all of the foregoing respects, and for additional reasons that willbe apparent from the following description, this invention differs fromand has advantages over Maude, US Pat. No. 2,967,467. In the Maudepatent, the Styrofoam can be routed out to some degree, but it isthereafter deformed by the use of a hot asphalt mastic which will meltthe Styrofoam. Also, the Styrofoam tends to leave a film on the concretesurfaces to impede the adherence of sealant to the concrete and destroythe watertight properties required of the joint.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspectiveview of the expansion joint assembly.

FIG. 2 is a view in lateral section through the expansion joint assemblyas positioned between two concrete slabs prior to removal of the toppingstrip.

FIG. 3 is a view in section similar to that of FIG. 2 illustrating theremoval of the topping strip.

FIG. 4 is a view in section similar to that of FIGS. 2 and 3 after theapplication of sealant.

FIG. 5 is a fragmentary perspective view of a modified expansion jointassembly incorporating a bond breaker strip.

FIG. 6 is a transverse sectional view of the expansion joint assembly ofFIG. 5 showing the topping strip removed and sealant applied in place.

DETAILED DESCRIPTION OF THE INVENTION The expansion joint assembly 10 ofFIG. 1-4 comprises an expansion joint strip 11 and a topping strip 12held together by staples 13. The expansion joint strip 11 and thetopping strip 12 are made of compressed wood fiber, such as is made inexpansion joint fillers by Homasote Company of Trenton, NJ. and soldunder the name Homex 300. The staples 13 are conventional metal stapleslong enough to fasten the topping strip 12 to the expansion joint strip11.

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FIGS. 2, 3 and 4 illustrate the process of applying and using theexpansion joint assembly 10. After a base 14 as been suitably preparedin the conventional manner, elongated units having the components of theexpansion joint assembly 10 as illustrated in FIG. I are positionedwhere expansion joints are to be located between concrete slabs. Thenconcrete is poured to form concrete slabs I5 and 16. It will be notedthat up to this point in the application, the expansion joint assembly10 has been supplied and handled as an integral unit consisting of theexpansion joint strip 11, the topping strip 12, held together by thestaples 13.

After the concrete has set, the topping strip 12 is removed as indicatedin FIG. 3. Removal of this topping strip 12 is easy and is done eitherby first prying the staples loose or by lifting one end of the toppingstrip 12 slightly and gradually pulling it free of the expansion jointstrip 11.

In the final step, the groove 17 that is exposed upon removal of thetopping strip 12 is filled with a suitable sealant. Any commercialsealant, such as a polysulfide, urethane or silicone may be used. Inthis embodiment, the sealant l8 bonds to the portions of the adjacentsides of the concrete slabs l5 and 16 which define the sides of thegroove 17 and bonds to the upper edge of the expansion joint strip 11which defines the base of the groove 17. When the sealant has dried, itforms a liquidtight seal to prevent moisture from seeping into the areabetween the concrete slabs l5 and 16.

It is important in this invention that the expansion joint assembly 10has no tar or asphalt additives and does not have the disadvantages of aStyrofoam material which would deposit a thin film on the adjacentsurfaces of the concrete slabs l5 and 16 and prevent adherence to thoseexposed concrete surfaces of cold-applied sealants. In addition, theexpansion joint strip 11 will not be melted or deformed if a hot asphaltmastic is used as the sealant 18.

The sealant 18 extends a uniform depth throughout the length of theexpansion joint because of the uniform height of the topping strip 12which was removed. This is in contrast with the usual routing of theexpansion joint filler that conventionally must be done before a sealantis applied.

FIGS. 5 and 6 illustrate a modification of the invention. This expansionjoint assembly 20 has an expansion joint strip 21 and an upper toppingstrip 22. A thin bond breaker 23 is located between the expansion jointstrip 21 and the topping strip 22. The bond-breaking strip 23 maycomprise a tape of any material to which the sealant to be used will notbond or adhere, such as an ethylene strip. The bond-breaking strip 23 isfastened to the upper edge of the expansion joint strip 21 by a suitableglue or adhesive. The topping strip 22 is removably secured to theexpansion joint strip 2] by staples 25 that extend through thebond-breaking strip 23 and into the expansionjoint strip 21. Alternativeto the tape 23, a bond-breaking surface may be applied to the upper edge24 of the expansion joint strip by coating the upper edge 24 with asuitable substance of plastic or other material that, when set, will notadhere to the sealant that is to replace the topping strip 22. In thisalternative form, the topping strip 22 is stapled to the expansion jointstrip 21 after such a liquid coating has set and dried.

FIG. 6 shows the process of using the expansion joint assembly 20 ofFIG. 5. After preparation of the base I4, elongated expansion jointassemblies 20 are located along the areas between proposed concreteslabs, such as the slabs I5 and 16. Thereafter, the concrete is pouredand sets to form the slabs l5 and 16. Once the concrete has set, thetopping strip 22 may be removed to expose a groove 26 of uniform depthdefined by the adjacent sides of the concrete slabs l5 and I6 and at itsbottom by the ethylene strip 23. The groove 26 is then filled withsealant 27 which bonds to those adjacent sides of the concrete slabs l5and I6 which define the sidewalls of the groove 26 but does notbond tothe ethylene strip 23. The result is a liquidtight seal bonded to theconcrete slabs I5 and 16 that will expand and contract with expansionand contraction of the groove 26 unimpeded by adherence to the base ofthe groove 26 defined by the ethylene strip 23. In this respect, theexpansion joint assembly 20, while slightly more costly than theexpansion joint assembly 10, has the advantage that the sealant 27 hasunimpeded lateral expansion and contraction.

The expansion joint assemblies and are such that they may be supplied inthe assembled packages illustrated in FIGS. 1 and 5. Manufacture of theexpansion joint assembly 10 is quick and easy. A conventional compressedwood expansion joint filler, such as the aforementioned Homex 300expansion joint filler, is selected for the desired expansion jointsize, the width of the expansion joint filler depending upon thethickness the expansion joint is to have. Then the compressed woodexpansion joint filler is cut lengthwise, preferably with a carbide tipsaw for a clean-sawn surface, to form the expansion joint strip 11 andthe topping strip 12. The topping strip 12 is then fastened to theexpansion joint strip 1 l with the staples 13 to complete the expansionjoint assembly 10.

In making the expansion joint assembly 20, the foregoing process isrepeated except that, prior to fastening the topping strip 22 to theexpansion joint strip 21 by the staples 25, the ethylene tape 23 isapplied to the upper edge 24 of the expansion joint strip 21. In bothexpansion joint assemblies 10 and 20, the assembled unit is ready forinstallation to be followed by simple removal of the staples 13 and thetopping strip 12 or the staples 2S and the topping strip 22.

Various changes and modifications may be made within this invention aswill be readily apparent to those skilled in the art. Such changes andmodifications are within the scope and teaching of this invention asdefined by the claims appended hereto.

What is claimed is:

1. An expansion joint assembly for use between concrete elementscomprising an elongated expansion joint strip permanently positionedbetween the concrete elements, a thin layer of material bonded to thetop edge of the expansion joint strip and being substantiallynonadherable to a sealant, an elongated topping strip removably attachedon the upper surface of the thin bonded layer, the assembly beingpositioned between the concrete elements with at least most of thetopping strip positioned below the upper surface of the concreteelements, whereby removal of the topping strip exposes a controlleddepth groove above the thin bonded layer for receiving a sealant which,as it expands and contracts, is unimpeded by contact with the thinbonded layer.

2. The expansion joint assembly of claim 1 wherein the expansion jointstrip and topping strip are of compressed wood.

3. The expansion joint assembly of claim 1 wherein the fastening meanscomprises removable rigid elements extending through the topping stripand into the expansion joint strip.

4. The expansion joint assembly of claim 3 wherein the rigid eiementsare staples.

5. The expansion joint assembly of claim 1 wherein the thin layer ofmaterial comprises a tape glued to the upper edge of the expansion jointstrip.

6. The expansion joint assembly of claim 5 wherein the tape is ethylene.

i i t

1. An expansion joint assembly for use between concrete elementscomprising an elongated expansion joint strip permanently positionedbetween the concrete elements, a thin layer of material bonded to thetop edge of the expansion joint strip and being substantiallynonadherable to a sealant, an elongated topping strip removably attachedon the upper surface of the thin bonded layer, the assembly beingpositioned between the concrete elements with at least most of thetopping strip positioned below the upper surface of the concreteelements, whereby removal of the topping strip exposes a controlleddepth groove above the thin bonded layer for receiving a sealant which,as it expands and contracts, is unimPeded by contact with the thinbonded layer.
 2. The expansion joint assembly of claim 1 wherein theexpansion joint strip and topping strip are of compressed wood.
 3. Theexpansion joint assembly of claim 1 wherein the fastening meanscomprises removable rigid elements extending through the topping stripand into the expansion joint strip.
 4. The expansion joint assembly ofclaim 3 wherein the rigid elements are staples.
 5. The expansion jointassembly of claim 1 wherein the thin layer of material comprises a tapeglued to the upper edge of the expansion joint strip.
 6. The expansionjoint assembly of claim 5 wherein the tape is ethylene.